1. Field of the Invention
The present invention relates to a hybridization method for nucleic acids, and in particular to a method using a hybridization device with the procedures modified, which shows advantages of simplicity and efficiency.
2. The Prior Arts
Nucleic acid hybridization with a probe is a method popularly used to identify the target DNA from a sample containing the desired gene or the nucleic acid fragment. Conventionally, the hybridization reaction was carried out by blotting or transferring the sample DNA to a substrate such as a membrane, hybridizing and pairing the nucleic acid with a probe having specificity, and then presenting the result of the hybridization by the probe-labeled present molecule in a presenting method such as coloring method, chemiluminescence method, and radiography method and so on. A blotting method in which a DNA sample transferred to the membrane by electrophoresis gel is hybridized with the probe is referred to as Southern blotting method. A blotting method in which a RNA sample transferred is hybridized is referred to as Northern blotting method. Other blotting method in which the nucleic acid to be analyzed is directly dropped is referred to as dot-/slot-/spot blotting method according to the dropping area. The dot-/slot-/spot blotting method is usually applied among the abovementioned methods in general qualitative analysis or in large batches of analysis, because the analyzing time can be shortened due to the needlessness of electrophoresis for separation and transfer, and the cost is low due to the needlessness of electrophoresis and transferring devises and various related agents.
The conventional blotting method is to directly drop the nucleic acid to be analyzed on the surface of a membrane. The nucleic acid to be analyzed is fixed by heating or radiation with ultraviolet to form covalent crosslinkage with the membrane thereon to prevent it from falling off in the subsequent hybridization and washing processes. Under the conventional condition, the nucleic acid to be analyzed is dropped in a wet membrane, which will further be diffused, penetrated and absorbed in the membrane surface. Therefore, it takes long time for the nucleic acid to be analyzed to absorb. On the other hand, during the addition of the nucleic acid probe contained in the blocking reagent for hybridization, the probe can only be diffused on the membrane surface in a similar way as the nucleic acid to be analyzed, finds and base-pairs with the complementary nucleic acid to be analyzed through Brownian motion. Therefore, the conventional hybridization reaction needs many procedures and more than 10 hours of the reaction time to proceed. The reaction cannot be finished in a short time even when the result is urgent needed. In addition, the method is non-economical if a lot of time and agents are used for simple qualitative tests of nucleic acid. Accordingly, it is necessary to develop a rapid blotting method or device in which the time and procedures for blotting analysis can be simplified and the background noise can be lowered. This will greatly enhances the efficiency, shortens the time needed for the experiment, and reduces the cost of the materials for either the simple tests or the large batches of analysis.